Pneumatic classifier



A. H. -sTEBBlNs yPNEUMATIC CLASSIFIER Filed June V15, 1925 lll ll/ Jan. 6` 11;@

Patented Jan. 6, 1925. v

UNITED sTArE-s PATENT, orrica ALBERT H. s'rnisims or Los ANGELES, foALIroair`m f i PNEUMATIC CLASSIFIER. f

Appiiation faied'nnie 15, i923; seriai No. 645,534.3

To all whom z'twnay concern."

Beit known that I, ALBERT I-I.4 S'rnizxfs,

va citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have inventedfau Improvement ,in Pneumatic.'Classiliers, of which the following description, in con-- nection withr the accompanying drawings, is

a specification, like characters on the drawings representing like parts. y

YThis inventionrelates tol pneumatic classi.

'fiers of a type in which the materialsto be treated are spread outsubstantially'radially from' a central-'position into thel path of rising air currents.

Pneumatic classifiers are adapted to separate materials in accordance jwith their differences yin specific gravityand to.` a less extent in accordancewith theirV differences 1in size, and the province of the present dcvice'is to classify materials, and to remove the fine 'particles with a high degree' of thoroughness. i

' One important feature of the present invention resides in novel means for delivering the materials to be treated into thepath of the rising air currents and for spreading out 'the'materials in substantially a radial direction. v f y Another important feature of the invention resides in la novel 'construction for' directing airvk currents upwardly'aroundthe material distributing imeans through the material andthen alonga tortuous path to remove the coarser particles vfrom the air.

Another important feature of the invention resides in the `construction whereby the materials being treated yare lmoved outwardly from a central point throughout the classifying operationl so that the materials yare progressively. thinned out as they'advance along the path of treatment. f l

Still another featureof the invention resides in novel means for regulating the lflow of materials to the distributing means.

Other features of the invention and novel combination of parts in addition tov the above will be hereinafterv described in connection with' the accompanying drawings which illustrate one thereof.

In the drawings: Fig. lis a verticalcentral sectional View through a pneumatic,I classifier constructed in accordance with the present invention;

4 Fig.l 2 is an enlarged view of the upper good practical forni portion of the distributing cone, 'part'beingIy shown 'in section, and" y p Fig. .3` is a` sectional' view takenr onthf- In the embodiment of the inventionillu's tratedA the classifying operation takes place` within the' closed casingv 10,v and this casing is shownas'si'ispended by'rods 11 the upper ends ofwliich are secured to 'a bin 12. The bin 12 may be supported by beams 13, and

if desired may be mounted within an gwen-v`v` ing formed in the* floor 14 of a buil The bin 12preferably hasy a downwardlyinclined bottom 15 at the, lower end of which is provided the.feed chute 16.

vWithin thecasing 10 is provided an upwardly extending 'separating wall 17 dis'-,r

lposed in spaced relation to the wallsof the casing and forming an inner chamber 1S and an outer chamber 19.1' The wall17 may beisupported within the .casing by they `brackets 20, and these -brackets preferably 'are positioned a substantialdistance below the upper endof vthe wall17 so that they will not interfere with theair currents adjacent the upper endof this wall'.l At they lower-end of the wall 17 is providedfa i* Y'is mounted 'in alignment with the Yaxis of v4the chute las shown. The cone 25'fshould be supported so that its supp'ortingfineans will not interfere with the air currents which are caused torise upwardly `around the cone,v and'in the'presentcase a pi`pe26 'is provided which l,extends laterally ywithin thev casing 10 near the lower end of the same and is ythen bent upwardly as at 27 andthe rupper end of this pipe is provided withan outwardly flaring` end 28 to which the lower end of the cone 251isfsecured.y i The feed chute -16 'delivers 'the' materials to be trea-tedupon the upper end ofthe cone "25, and the rate at which Ithes'ei'materials are discharged at'the'lower end 0f the chute niaybe regulated byiprov-idingfthe chute with an adjustable extensiony 29 which eX- n tends downwardly over the upper end p'ortion' of the cone as shown, and this extension may be raised or lowered relative to the cone by adjustable bolts 30 having supporting engagement with the'upper end "of the extension 29.-

To prevent the materials within the feed-v chute from becoming packedor clogged at theA lower end of the extension 29, the upper end` portion of thecone is provided wlth a number of downwardly inclined apertures lodge any particles that mightr tend to becomestuck at this point.

As the materials to-be treated escape from the lower end of the extension 29 they will is provided with a second set of apertures 32 through. which jets of air mayy escape from the cone in substantially a'horizontal direction to blow lthe materials outwardly towards the annular wall 17. These yapertures are preferably made relatively small so that a large volume of air will not escape from the interior of the cone 25, but the air 4result that they are vspread out more and should escape from. the apertures 31 and 32 with a 'substantial degree of force so that a small amount of air will act with the desired effect upon the materials.

Within the casing 1 0 in thel present-con struction is provided a downwardly extendingy wall 33 the lower end of which surrounds the upper end of the wall 17 in spaced relation thereto and` extends into overlapping relation with Ithe wall 17, as will be Vapparent from Fig. 1.- The wall 33 may bey supported by a conical portion 34 that extends upwardly to a sleeve 35 surrounding the extension 29. f

Classilication or separation of the materials is effected by producing air currents that pass upwardly within the chamber 18 about the distributing cone 25 and through the materials thrown outwardly `from the cone by the jets of air escaping through the apertures 32. The 'rising air currents are caused to pass over the upper end of the annular wall 17 and thendownwardly between this wall and the wall 33, as indicated by the arrows, and then pass around the lower endof the wall 33 and upwardly Within the casing 10. This is accomplished by providing means for exhausting air within the upper portion of the casing 10 about the walls 33 and 34, and to ythisend a conduit f 36 is provided which maybe connected to a suction fan or other form of exhaust means. The conduit 36 may lead from an annular `chamber`37 formed within the wall 38'which surrounds the feed chute, and this wall ex tends upwardly from a cover 39 secured to the upper end of the casing 10. The air which rises withinvthe inne-r chamber 18 may be admitted to this chamber by aconduit l0 which islarger than the pipe 26 and surrounds the same` and the conduit extends inwardly through a lateral Qwall of the casing 10 and upwardly within the chamber 18,',and air at atmospheric pressure may be drawn in through the outer open end of this conduit `into. the chamber 18 and vupwardly along the path indicated by the arrows. The amount of air admitted through thev conduit Llois controlled by the adjustable. gates y4:1, and the amount -of airexhausted from the casing 10 maybe controlled by adjusting the gate 42 within the conduit 36.

From the foregoing it will be understood that a relatively smallv amount ,of air is forced into the cone 25 through the pipe 26 and escapes through the apertures 31 and 32 with substantial forcea'nd it will be understood that most of the air used withinthe present devicewenters the chamber 18 through the conduit 40.and` is exhausted from the upper portion of the casing 10 through the conduit 36.

It 'should be noted that throughout the treatment of the materials theyare moved outwardly from a central point, with ythe more as they advance along the path of treatment; so that the air will act upon the materials with increasing thoroughness as the latter passes fromy one chamber to the other. vThe' construction shown by. which the airis `caused to make a sharp turn at the upper end ofthe inner wall 17, and also about the lower end of the wall 33, is important because these sharp bends assist materially in releasing Athe heavier particles from the traveling' ai'r currents.v

Some of the materials which remain sus pendedin the air as the latter travels around the lower end of the wall 33'may be thrown outwardly butr not entirely released from the traveling air currents, and an 'annular delecting plate 43 is therefore provided, ex-

. that the heavier particles thrown outwardly from the cone 25 will not be lifted over the separating wall 17, so that these particles will settle downwardly in the chamber 18 v be dislodged from the air currents by the sharp bend o-f the airabout the lower end of the wall 33,`it being understood that the de# fleeting plate '43 will assist in removing these particles from the air as it rises about the wall 33,and as a 'resultl of the present construction all-but lthe very fine particles will be removed from'the air before it escapes from the upper end'of the casing 10.

The cone and walls 17 and 33 are preferably mounted centrally within the casing 10, so that air currents of equal strength will be produced entirely around the parts just mentioned, and the materials will" be simi-` larly treated upon all sides'ofpthe distribut' ing cone., y 1 f 'A Narrow supporting blocks 44 and 45' may be interposed between the pipe 26 and conv duit 40 to support lthe formerA centrally within the latter." 'Should it be. found th'at "the materials vforced outwardly by the jets of airv escaping through the apertures` 32 A"tend to wear awaythe inner face of the 'separating wall' 17 this may be prevented by providing slight inwardly extendingy shelves or lflanges 46 'upon which materials may p lodge to protect the inner face of the wall.

The pneumatic classifier of thefpresent invention isfree from'working'parts, is inexpensive to install and operate, and in addition to classifying materials, will remove thoroughly the very fine particles from the materials being treated. Y

What is claimed is:

1. A pneumatic classifier comprising, in combination, a casing, an upwardly'extending cone Adisposed centrally withinthe casing and having apertures in its inclined walls, a feed chute for delivering materials to be treated upon the cone to slide down the inclined cone walls, a wall surrounding the cone in spaced relation thereto, and means for producing al iiow of air through said apertures and upwardly over the wall to lift the lighter particles over the wall without lifting the heavier particles over the same.

2. A pneumatic classifier comprising, in combination, a casing, an upwardly extend# ing cone mounted centrally within the casing, a feed chute for delivering materials-to be treated upon the cone to slide down the inclined cone wal-ls and extending downwardly over the upper end of the cone, means `for forcing air through the sides of the cone adjacent its upper end to force materials through the space between the cone and end of the feed chute, a wall surrounding the cone in spaced relation thereto, and means for producing a flow of air upwardly between thecone and wall to lift the lighter `particles over the wall without lifting the heavier particles overthe same.y

3. A pneumatic classifier, comprising, iny

combination, a closedcasing, j an annular"l 'separating -wall disposed centrally within said casing and exten'ding'upwardly:therein to form an inner and 1an' outer chamber within the casing, a second annular -w'all within lthe casingextending downwardly in spaced overlapping relation about'thev upper end of the separating wall, an upwardly extending cone within said inner chamber, means'for delivering 'materials to be treated to the `cone yto. slide, downwardly upon its sloping walls, a."conduit for conducting air into the inner chamber and'having its discharge end' positioned below the conesothat the latter prevents thematerials from enterj. ing lthe conduit and means for exhausting' air fro-m the :up-per 'portion ofthefc'sing, about said second wallto produce air currents that rise within the inner chamber and passup'wardly'over the "end ofthe separatin'g walland downwardlyi'about the end of"l the second wall` with a sharp bend'to remove thelighter particles 'from the heavier particles. v v

4. A pneumatic classifier comprising-,1n

:combination` av closed casing, fan annular separating A wall extending upwardly7 within the casing and forming an inner and an outerv chamber,"A a second 'annular wall within the casing' extending downwardly therein in spaced overlapping relation about the upperv end of the separating wall, means for deliyering'the materials 'to'pbeI treated into said inner chamber with spreading effeet, an 'annular material arresting flange surrounding and positioned nearl but in spaced relationto the lower end of said second wall, and means for exhausting air from the upper portion of the casing about said second wall to produce air currents that rise within the inner chamber and pass upwardly over the end of the separating wall and downwardly about the end of the second wall to remove the lighter particles. from the heavier particles.

5. A pneumatic classifier comprising, in combination, a closed casing, a pair of annularA walls within said casing extending toward each other so that the end of one surrounds the end 'of the other in 'spaced overlapping relation, means for delivering the materials to vbe treated into the chamber enclosed by said walls with spreading effect, an annular ange supported adjacent the end of one wall and positioned to arrest the heavier particles withinl the air which are thrown outwardly by the sharp turn of the air in passing around the end of one wall, and means for exhausting air from around one of said walls to cause air currents to around the end of the other wall with a" sharp bend around the end of each wall to remove the lighter materials Withoutremoving the heavier materials,

' 6. A pneumatic classifier comprising, in

" p combination, a casing, an upwardly extending cone within said casing and havingapertures in its inclined walls, means for delivering materials` to be treated upon the cone, means for forcing air through l said apertures to throw the materials-out in a,`-

' over the upperend of said cone for delivering materials thereto, means forforcing air outwardly through said apertures to force materials Vfrom the endof-said chute, and means for passing. currents of air through the materials as the latter leave the dis-- tributor. y Y y 8. A pneumatic classifier, comprising, in combination, a closed casing, an annular separating wall mounted within the casing and extending upwardly thereinto form an inner and an outer chamber, an air conduit extending upwardly within the inner chamber, an upwardly extending cone withinthe inner chamber supported over said conduit and having air discharge openings, a tube mounted within said conduit to supply air to the cena-means for deliveringthe materials to be treated kto said cone to slide down the inclined cone Walls,`andmeans for prokducing a flow of airupwardly between the yseparating wail and .cone and over the wail to liftl the `lighter-particles over the wall Without lifting. the heavier particles ovcr the same.

9. A pneumatic classifieiglcomprising, .in combination, a closed casing, an. annular separating wall disposed centrally within said casing and extending upwardly therein to form an inner and an outer `chamber Within the casing, Va second annular wall` Within the casing extending downwardly in spaced overlapping relation about the upper end of the separating wallan air conduit extending upwardly within the inner chamber, an upwardly extending cone ywithin the inner chamber supported over'said conduit so that materials sliding down the walls of the cone will not enter the conduit, means for delivering materials to bev treated to the cone., and means for yexhausting air from the upper portion of thecasing about said second wall to produce.aircurrentsthat rise within the inner. chamber and pass upwardly over thevendy of the separating wall and downwardly. kabout theend of the second Vwall to remove the'lighter` particles from the heavier particles.

In testimony whereof, 4I have signed my name to this specification.

ALBERT H. srEBBiNs. 

